Video of me hitting

[AceInfinity]

The whole line in football requires minimal skill

This is where you're a bit misguided. Whether it's based on your lack of knowledge for football remains unknown, but it's basically the same mentality in the response NekoChan had given. Throwing and making sure the ball gets there fast, is just as tough as the pressure involved in knowing that you need to catch that ball on the run, while focusing on your surroundings, and making sure that you have the ability to change gameplay if something unexpected from the play happened.

Anybody who is fit, huge, and can spend a day or two on proper tackling form can be a linebacker

This is like saying anyone who can catch a ball, can be a catcher in baseball. They don't have to run, they just sit there and catch a ball.

If you're big and you play baseball...that doesn't make you immediately good at hitting

Same in football, you don't need to be big to tackle, there's small guys out there that can stop just as many people.

It takes much longer to learn the techniques in baseball than in football when it comes to that

Where's the stats in that to prove this? You're comparing "hitting" to something in baseball here? What about kicking in baseball, or catching, and throwing, in addition with speed and agility?

You'd have to have played both sports to understand.

Have you? And thoroughly enough to state this? Have you been every position on a football team?

I already stated that the two can't be compared at all period. There's little to no chance that a football player can swap places and have a chance at football and vice versa.